Puffer-type compressed-gas circuit interrupter with double-flow action

ABSTRACT

A puffer-type compressed-gas circuit interrupter is provided having a movable cylinder movable with the movable contact structure, and being provided with a hollow contact follower disposed within the moving contact structure. The hollow contact follower has a lost-motion connection with the movable contact structure, and maintains abutment and a blocking of the gas flow with the hollow stationary contact until a predetermined time, thereby blocking the venting action, and permitting a precompression of the gas. Further opening motion of the movable cylinder and the movable contact structure pulls the hollow contact follower away from the hollow stationary contact, and provides a double-flow venting action through both the stationary hollow contact and also the moving hollow contact.

tates Patent [1 Leeds PUFFER-TYPE COMPRESSED-GAS CIRCUIT INTERRUPTER WITH DOUBLE-FLOW ACTION Oct. 30, 1.973

Primary Examiner-Robert S. Macon Attorney-A. T. Stratton et al.

[5 7] ABSTRACT A puffer-type compressed-gas circuit interrupter is provided having a movable cylinder movable with the movable contact structure, and being provided with a hollow contact follower disposed within the moving contact structure. The hollow contact follower has a lost-motion connection with the movable contact structure, and maintains abutment and a blocking of the gas flow with the hollow stationary contact until a predetermined time, thereby blocking the venting action, and permitting a pre-compression of the gas.

Further opening motion of the movable cylinder and the movable contact structure pulls the hollow contact follower away from the hollow stationary contact, and provides a double-flow venting action through both the stationary hollow contact and also the moving hollow contact.

9 Claims, 4 Drawing Figures PUFFER-TYPE COMPRESSED-GAS CIRCUIT INTERRUPTER WITH DOUBLE-FLOW ACTION CROSS-REFERENCES TO RELATED APPLICATIONS ln'United States patent application filedqlan. 8, I968. Ser. No. 696,415, now abandoned, and cont nued ,n..uneq,stas ratqatuarrli filed No. 3, 1972, Ser. No. 303,579 by Stanislaw A. Milianowicz, entitled Gas-Blast Circuit Interrupter With Insulating ArcShield, there is illustrated and' BACKGROUND OF THE INVENTION It has been known for many years by those skilled in the art that are interruption may take place by means of piston structures operated mechanically and, in some instances, being assisted by are generated pressure, or by differential-piston action. An example of such a type of puffer interrupter is set forth in United States patent, issued Oct; 18, 1960, to Winthrop M. Leeds, as U.S. Pat. No. 2,957,063, and assigned to the assignee ofthe instant application. There are many other United States patents illustrating various types of piston structures utilized to compress gas, and to force the compressed gas into the arcto effectits extinction. Some of these patents are as follows: U.S. Pat. Nos. 2,788,418 Owens et' al.; 3,331,935 Milianowicz; 2,979,591 Friedrich and 3,524,957 Frink.

According to the present invention, it is desired to provide an improved puffer-type circuit interrupter in which a spring-biased arcing contact follower blocks the vent in the hollow stationary contact until the pumping cylinder, finger-contact assembly, and insulating flow guide have moved a predetermined distance.

This permits thereby a pro-compression of the gas, such as sulfur-hexafluoride (SP gas, for exiample,.until the follower separates. from the stationary contact and draws. an arc. At this time, the compressed gas is directedinto the arc column, and thence through both the hollow vented follower and also the hollow tubular stationary contact, thereby giving a double-flow gasblast action of the are for maximum arc-interrupting effectiveness.

Accordingly, it is a general objectof the present invention to provide an improved puffer-type circuit interrupter in which pre-compression of the gas occurs, until a proper subsequent time at which the arc is drawn, and the pre-compressed gas utilized to effect rapid arc extinction.

Another object of the present invention is the provision of an improved puffer-type circuit interrupter in which pro-compression of the gas occurs during a finite time, by the utilization of a hollow contact follower, having a lost-motion connection with respect to the moving-contact structure, and the device being such that in the open-circuit position, there are no creepage paths along insulating surfaces in the fully-open circuit position of the device.

Still a further object of the present invention is the provision of an improved piston-type circuit interrupter utilizing a movable hollow cylinder sliding over a stationary fixed piston, the moving hollow cylinder having attached therewith an orifice structure, hollow movable contact structure, having interiorly disposed therewithin a hollow contact follower.

Still a further object of the present invention is the provision of an improved puffer-type circuit interrupter of the type set forth in the immediately preceding paragraph, having in conjunction therewith, an interiorlydisposed arc-catcher to provide a termination point for the end of the arc column at a favorable location within the hollow contact follower.

Another object of the present invention is the provision of an improved puffer-type circuit interrupter having the capacity for pro-compression of the gas, and involving relatively few parts.

Another object of the present invention is the provision of an improved puffer-type circuit interrupter in which blockage of the gas flow is afforded by the utilization of a hollow contact follower having a lost motion-connection with the moving hollow contact structure.

'Another object of the present invention is the provision of an improved puffer-type circuit interrupter with a central arc-catcher that takes up a favorable location in a reduced electric field after a pre-selected displacement of a hollow contact follower by means of a lostmotion connection to the moving contact structure.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings.

a gret DESCRIPTION or THE DRAWINGS FIG. 1 is a vertical sectional view taken through a .puffer-type circuit interruptenadaptable for outdoor use, and at a relatively high voltage, the contact structure being illustrated in the closed-circuit position;

FIG. 2 is a view similar to that of FIG. 1, but illustrating the disposition of the several parts during the precompression of the gas and prior to a separation of the Contact structure.

FIG; 3 illustrates the disposition of the several parts at a later point in .the opening operation with the gas flowing into the arc, and providing a double'flow gasblast action;-

FIG. 4 illustratesthe fully-open circuit position'of the puffer-type-circuit interruption of the present invention, illustrating the absence of creepage surfaces between the separated contacts at widely-different voltages.

DESCRIPTION OF THE PREFERRED EMEQDIMENT Referring to FIG. 1 of the drawings, the reference numeral 1 generally designates a puffer-type circuit interrupter, including a pair of upstanding cylindrical-casing members 2, 3 formed of insulating material of the requisite strength, and clamped by annular support rings 4, 5, to an intermediately-disposed contact support plate 6. A separable contact structure 8 is provided, including a stationary tubular contact, designated by the reference numeral 10, and fixed in any suitable manner, as by a threaded adjustable connection 10a, to an upper support plate 12 having an upper dome portion 12a integrally formed therewith. An outwardly-jutting terminal-pad portion maybe provided, designated by the reference numeral 14, to which a line connection L may be secured.

Cooperating with the stationary tubular contact is the movable contact structure'l6, comprising a cluster of circumferentially-disposed contact fingers 17, encircled by a pluralityof'garter springs 19, and biasedinvided by an upstanding contact portion 23, formed as an integral part of an operating cylinder 25, which is moved downwardly by the operating rod 27 over the stationary fixed piston 29. As a result, as will be obvious, compression of the gas within the region 31 occurs upon downward driving motion of the surrounding puffer cylinder. 25 over the fixed piston 29, and a forceable flow of gas upwardly through the plurality of openings 33 provided in the upper end of the piston cylinder As'will be apparent from F IG; 2, there is a-blockage of gas flow through the hollow stationary contact 10, and also through the hollow'moving contact 16, because of the valve action of the hollow contact follower 35, biased upwardly by the spring 36, and having a lostary contact 10 and also through the hollow movingi contact structure 16, with the arc terminating at the arc horn 41, and alsorunning upwardly along the inner surfaces 10c of the stationary-contact 10. Because of the A strong blast action from the pre-compressed gas, are extinction quickly ensues, and further'downward opening motion of the hollow operating cylinder 25 and the moving contact structure 16 provides a wide isolating break with no insulating surfaces between the separated contacts, which at high voltage 'couldconceivably result. in creepag'e paths with carbon formation and possible flashover. It will be noted, as shown in FIG. 4,

that a wideoperi isolating gap 43 is provided in clean SF g'as 45'which fills the container 47, insuring thereby that no fiashover occurs. 1

Preferably, sulfur-'hexafluoride (SFG) gas is utilized as the arc-extinguishing gas, but it will be obvious to those skilled in the art that other gases or' fluids could be uti- Thisimportant double-flow action is accomplished by making the contact follower hollow, with an orifice opening 49 at the top. An additional important feature of my invention is the central arc-catcher rod 41, which, in the closed position of the contacts, protrudes through the follower orifice 49. In the arcing position,

illustrated in FIG. 3, the arc-catcher 41 is below the orifice 49, where the hot arc terminal is out of highlystressed contact gap region. However, the arc section I inside the follower 35 is kept short, so that unnecessary are energy will be avoided that might lead to clogging of the restricted venting below the follower 35.

Although there has been illustrated and described a specific puffer-type circuit interrupter, it is to be clearly understood that the same was merely for the purpose of illustratiomand that changes and modificationa may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

What is claimed is:

1. A circuit interrupter'of the fluid-blast type, including separable-contact means comprising a relatively stationary hollow tubular venting contact and a cooperable hollow, movable contact structure, a movable operating cylindertaffixed to said movable contact 2:29PM?- i 1a!1.s ini relatively Stationary piston, said movable piston cylinder sliding over said relatively stationary piston to'compress gas within the a movable operating cylinder, an orifice structure carried by the movable operating cylinder and having an orifice opening closely encircling said stationary hollow contact, and ,a movable follower-contact structure movable with the movable contact structure and having a lost-motion connection with the movable operating cylinder to provide a valve action and thereby temporarily prevent the exhausting of gas through the separable contact structure;

2. The combination according to claim 1, wherein the movable follower-contact is hollow. 3. The combination according to claim 2, wherein the movable follower has an arc-catcher rod'protruding through the opening thereof in the closed-circuit position of the circuit interrupter;

4. The combination of claim 1, wherein biasing means are provided to bias the hollow contact-follower against the relatively stationary contact in the closed position of the interrupter.

5. The combination according to claim 1, wherein the n1ovable contact structure is hollow and vents to the interior of a surroundingcasing.

6. The combination according to claim 1, wherein an upstanding casing structure is provided, said casing structure having a lower-disposed contact-support plate, andlsaid stationary fixed piston is; supported upwardly from said stationary plate structure. 7. A high-voltage pumped-gas circuit interrupter comprising a pair of upstanding insulating casings having an interposed contact-support plate provided there between, line-terminal means provided at said contact support plate, an upstanding fixed piston rigidly 'secured to said control-support plate, a'movable operating cylinder carrying a hollow movable contact structure sliding over said fixed piston, and relatively stationary hollow contact structure cooperating with said movable contact structure to establish an arc, and a concentrically-arranged interiorly-disposed contact follower of tubular configuration movable with the movable contact structure, and having a lost-motion connection with respect to said movable contact structure.' t

8. The combination according to claim 7, wherein an arc-catcher rod is fixedly secured to said movable operating cylinder and extends in the closed position of the breaker through the orifice associated with the movable contact-follower.

a 9. The combination of claim 8, wherein the tip of the said arc-catcher rod being placed in a position'below the orifice in the hollow movable contact follower after a predetermined displacement of the said follower during the initial part of the contact opening movement. =0: s 

1. A circuit interrupter of the fluid-blast type, including separable-contact means comprising a relatively stationary hollow tubular venting contact and a cooperable hollow movable contact structure (16), a movable operating cylinder affixed to said movable contact Structure (16), means defining a relatively stationary piston, said movable piston cylinder sliding over said relatively stationary piston to compress gas within the movable operating cylinder, an orifice structure carried by the movable operating cylinder and having an orifice opening closely encircling said stationary hollow contact, and a movable follower-contact structure movable with the movable contact structure and having a lost-motion connection with the movable operating cylinder to provide a valve action and thereby temporarily prevent the exhausting of gas through the separable contact structure.
 2. The combination according to claim 1, wherein the movable follower-contact is hollow.
 3. The combination according to claim 2, wherein the movable follower has an arc-catcher rod protruding through the opening thereof in the closed-circuit position of the circuit interrupter.
 4. The combination of claim 1, wherein biasing means are provided to bias the hollow contact-follower against the relatively stationary contact in the closed position of the interrupter.
 5. The combination according to claim 1, wherein the movable contact structure (16) is hollow, and vents to the interior of a surrounding casing.
 6. The combination according to claim 1, wherein an upstanding casing structure is provided, said casing structure having a lower-disposed contact-support plate, and said stationary fixed piston is supported upwardly from said stationary plate structure.
 7. A high-voltage pumped-gas circuit interrupter comprising a pair of upstanding insulating casings having an interposed contact-support plate provided therebetween, line-terminal means provided at said contact support plate, an upstanding fixed piston rigidly secured to said control-support plate, a movable operating cylinder carrying a hollow movable contact structure sliding over said fixed piston, and relatively stationary hollow contact structure cooperating with said movable contact structure to establish an arc, and a concentrically-arranged interiorly-disposed contact follower of tubular configuration movable with the movable contact structure, and having a lost-motion connection with respect to said movable contact structure.
 8. The combination according to claim 7, wherein an arc-catcher rod is fixedly secured to said movable operating cylinder and extends in the closed position of the breaker through the orifice associated with the movable contact-follower.
 9. The combination of claim 8, wherein the tip of the said arc-catcher rod being placed in a position below the orifice in the hollow movable contact follower after a predetermined displacement of the said follower during the initial part of the contact opening movement. 